Bit Patterned Media (BPM) and Energy Assisted Magnetic Recording (EAMR) are the primary technologies that are being investigated to overcome the Super Paramagnetic Limit (SPL) of perpendicular magnetic recording (PMR). While BPM awaits a fabrication technology that achieves performance at low cost, EAMR is struggling with media performance and head reliability. Therefore, the dark horse approach, microwave assisted magnetic recording (MAMR), is looking attractive to achieve gains of up to twice conventional levels in areal density (AD) with minimal changes in the associated heads and media.
MAMR approaches often include improved spin torque oscillators (e.g., such as those described in U.S. Pat. No. 7,616,412) that appear to show great promise for gains in areal density. However, as the component geometries are shrunk to achieve the gains in areal density, problems such as adjacent track interference (ATI) can become prevalent. As such, an improved MAMR system that reduces adjacent track interference (ATI) is needed.